Boring jigs have been available for boring aligned cross bores and edge holes in doors for mounting latch and lock devices. Typically they include a pair of spaced jaws with a guide between them. One jaw carries a threaded bushing for engaging the threaded shaft of an auger or drill, the other a hole whose diameter matches that of the drill and which may have a raised anti-splinter edge. The guide has a hole in it sized to receive the auger bit or drill for drilling the edge hole. There are means to adjust the spacing between the jaws and means to clamp the jaws in the door. Since the anti-splinter edge is integral with the hole in the jaw, that hole can only accommodate one size drill. Similarly, since the bushing is threaded it receives but one size drill shaft and that must be threaded; thus power-driven drills are not useable. The edge hole guide accommodates but one size auger and also has no means to receive a power drill. In addition, there is no provision to alter backset distance or to accommodate for bevel edge doors. Without such accommodation latch and lock installations in bevel edged doors often do not properly mate with the plate in the door jamb. In one device there is a backset adjustment but it requires a screw driver to loosen and retighten a set screw; a splinter ring is mounted in the same way; and the backset guide uses fixed, vertically extending plates. For quick insertion and release of the cross bore auger or drill there is a split bushing which is secured by a bolt and nut. Typically this arrangement may result in overtightening, resulting in excessive thread wear, or undertightening, resulting in threads being stripped. The use of set screws to secure the splinter ring and adjustable backset guide requires the installer to carry a screw driver just for the set screws. Conventional jigs tend to be heavy, awkward, difficult to align and set, and require other supporting tools such as wrenches, hex keys and scales.